Android มีปัญหาในการคิวรี่ข้อมูลกลับมาเป็น json จาก Mysql เมื่อส่งค่าเป็น BasicNameValuePair("tid",Integer.toString(tID)) ค่ะ

package app.classattendance;

import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;

import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class TeacherHomeActivity extends Activity {
	
	TextView txtsemester;
	TextView txtnameUser;
	String semester = "0";

	//private static final String name = "name";

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_teacher_home);
		
		final Button btnLogout = (Button) findViewById(R.id.btn_logout);
		final Button btnHome = (Button) findViewById(R.id.btn_home);
		
		btnLogout.setOnClickListener(new view.OnClickListener(){
			public void onClick(View v) {
				Intent intent = new Intent(TeacherHomeActivity.this,LoginActivity.class);
				intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
				startActivity(intent);
				finish();
			}
		});
		
		btnHome.setOnClickListener(new view.OnClickListener(){
			public void onClick(View v) {
				Intent intent = new Intent(TeacherHomeActivity.this,TeacherHomeActivity.class);
				startActivity(intent);
			}
		});
		
		txtnameUser = (TextView)findViewById(R.id.name);
		txtsemester = (TextView)findViewById(R.id.semester);
		
		String url = "http://10.0.2.2/phpFile/teacherMenu.php";

		Bundle extras = getIntent().getExtras();
		int tID = extras.getInt("userID");
		
		Intent intent= getIntent();
		String username = intent.getStringExtra("username");
		txtnameUser.setText(username);
		 
		List<NameValuePair> params = new ArrayList<NameValuePair>();
		params.add(new BasicNameValuePair("tid",Integer.toString(tID)));
		
		String resultServer = getHttpPost(url,params);
		
		try {
			JSONObject c= new JSONObject(resultServer);
			
			semester = c.getString("name");
			
			
		} catch (JSONException e) {
			Log.e("log_tag", "Error parsing data " + e.toString());
		}
		
		txtsemester.setText(semester);
	
	}
	
	public String getHttpPost(String url, List<NameValuePair> params) {
		String result = "";
		InputStream is = null;
		
		//ส่วนของการเชื่อมต่อกับ http เพื่อดึงข้อมูล
		try {
			HttpClient client = new DefaultHttpClient();
			HttpPost httppost = new HttpPost(url);
			httppost.setEntity(new UrlEncodedFormEntity(params,"UTF-8"));
			HttpResponse response = client.execute(httppost);
			HttpEntity entity = response.getEntity();
			is = entity.getContent();
		} catch (Exception e) {
			Log.e("log_tag", "Error in http connection " + e.toString());
		}
		
		//ส่วนของการแปลงผลลัพธ์ให้อยู่ในรูปแบบของ String
		try {
			BufferedReader reader = new BufferedReader(new InputStreamReader(
					is, "iso-8859-11"), 8);
			StringBuilder sb = new StringBuilder();
			String line = null;
			while ((line = reader.readLine()) != null) {
				sb.append(line + "\n");
			}
			is.close();
			result = sb.toString();
		} catch (Exception e) {
			Log.e("log_tag", "Error converting result " + e.toString());
		}

		return result;
	}
	

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.activity_teacher_home, menu);
		return true;
	}

}

<?php

	$hostname_localhost ="localhost";
	$database_localhost ="classattendance";
	$username_localhost ="****";
	$password_localhost ="****";
	$localhost = mysql_connect($hostname_localhost,$username_localhost,$password_localhost) or
	trigger_error(mysql_error(),E_USER_ERROR);

	mysql_select_db($database_localhost, $localhost);

	$tid = "9";
	$query_semster = "SELECT s.name as name
						FROM tbl_user u
						JOIN tbl_teacher t ON u.id = t.userId
						JOIN tbl_courseinfo cinfo ON cinfo.teacherId = t.id
						JOIN tbl_course c ON cinfo.courseId = c.id
						JOIN tbl_semester s ON c.semesterId = s.id
						WHERE s.active = 1 AND u.id = '".$tid."' GROUP BY s.name ";
	$exec_semster = mysql_query($query_semster) or die(mysql_error());
	
	if($result =mysql_fetch_assoc($exec_semster)){ 
		$arr['name'] = $result["name"];
	}
	
	echo json_encode($arr);
	
	mysql_close($localhost);
?>